Nauseous and gagging...? Why..? 19..

I'm 19 and in nursing school and have been gagging, feeling nauseous, puking from off smells (when someone uses the bathroom or a spicy food or strong smelling food) , and eating more than usual lately.

I am on Nexplanon and got that implanted in my arm on March 29th 2017.

Nobody has ejaculated in me yet with it.

I do have a friends with benefits, and we have sex about 4 times a week. We ALWAYS use a condom. Hell I even use a condom for oral sex because of STI possibilities. I over protect.

Anyways, I'm not use what could be causing it.

Even if a drop of semen touched my vaginal area, which I highly doubt?

I'm like 99.9% I'm not pregnant.

Could my birth control randomly make me very nauseous, gaggy, pukey, and raise my appetite evem after almost 5 months after insertion...?

What do you think?